1. Field of the Invention
This invention relates to a door closer having an arm with a traveler on its distal end, the traveler engaging a track on the top of the door. More specifically, this invention relates to a door closer having on its arm a traveler with a plurality of ball-shaped rollers engaging opposite concave faces of a track mounted on the top of the door.
2. Description of the Related Art Including Information Disclosed Under .sctn..sctn.1.97-1.99
It has been customary in the prior art to provide on the end of a one-piece arm of a door closer a downward shaft journaling a single roller engaging an upwardly-facing track of C-shape cross section. An example is disclosed in U.S. Pat. No. 4,287,639, which issued Sept. 8, 1981 to Arthur M. Denton. Such arrangements, while conventional in the art and which are shown in expired patents, have been known to have drawbacks. Specifically, because the C-shape track is upwardly facing, in bad environments it can accumulate dust and dirt to the extent that such debris becomes encrusted in the track and on the roller and can jam the action of the roller on the track.